The Journal of Contemporary Dental Practice

Register      Login

SEARCH WITHIN CONTENT

FIND ARTICLE

Volume / Issue

Online First

Archive
Related articles

VOLUME 12 , ISSUE 3 ( May-June, 2011 ) > List of Articles

RESEARCH ARTICLE

Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching

Carlos Rocha Gomes Torres, Patrícia Marra de Sá, Raffaela Di Iorio Jeronymo, Karen Cristina Kazue Yui, Eduardo Galera da Silva, Maria Filomena Rocha Lima Huhtala, Ana Paula Martins Gomes

Citation Information : Torres CR, de Sá PM, Jeronymo RD, Yui KC, da Silva EG, Huhtala MF, Gomes AP. Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching. J Contemp Dent Pract 2011; 12 (3):158-163.

DOI: 10.5005/jp-journals-10024-1027

Published Online: 01-02-2012

Copyright Statement:  Copyright © 2011; The Author(s).


Abstract

Aim

This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching.

Materials and methods

A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled water (control group); (b) sodium perborate and distilled water; (c) sodium perborate and 10% carbamide peroxide; (d) sodium perborate and 35% hydrogen peroxide; (e) 35% hydrogen peroxide. The teeth were stored in vials containing distilled water and the pH values of the medium surrounding the teeth were analyzed. After 7-day storage, the bleaching agent was removed and replaced by calcium hydroxide, and the distilled water was changed, in which the teeth were kept stored for further 14 days. Measurement of pH of the external medium (distilled water) was performed 7 days after insertion of the bleaching agents, immediately, 7 and 14 days after insertion of the calcium hydroxide. Data were submitted to statistical analysis by the two-way ANOVA and Tukey, s test.

Results

There were pH changes of the external medium at 7- day period after bleaching procedures. These results confirmed the diffusion of bleaching agents to the external medium.

Conclusion

Calcium hydroxide increased the external medium pH and was effective for pH alkalinization after intracoronal bleaching.

Clinical significance

Intracoronal bleaching of endodontically treated teeth may cause cervical root resorption. A possible explanation for this process is the passage of bleaching agents to the periodontal tissues yielding an inflammatory process. In an attempt to keep the neutrality of the periodontal pH, the calcium hydroxide has been recommended. Results of this study showed that this material should be always used after intracoronal bleaching.

How to cite this article

de Sá PM, Jeronymo RDI, Yui KCK, de Silva EG, Huhtala MFRL, Torres CRG, Gomes APM. Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching. J Contemp Dent Pract 2011;12(3): 158-163.


PDF Share
  1. Influence of postbleaching time intervals on dentin bond strength. Braz Oral Res 2004;18:75-79.
  2. Bleaching of vital and nonvital teeth. Curr Opin Dent 1992;2:142-49.
  3. A review of the safety of tooth bleaching. Dent Update 200936604-06. 608-10, 612-14.
  4. A technique for staining extracted teeth: A research and teaching aid for bleaching. J Endod 1982;8:67-69.
  5. Chemical agents for removing intrinsic stains from vital teeth. Technique development. Quintessence Int 1989;20:323-28.
  6. Bleaching of a discoloured nonvital tooth: Use of a sodium perborate/water paste as the bleaching agent. Int J Paediatr Dent 1997;7:35-38.
  7. Ex vivo evaluation of the effectiveness of bleaching agents on the shade alteration of blood-stained teeth. Int Endod J 2008;41:485-92.
  8. Can previously bleached teeth be bonded safely? Am J Orthod Dentofacial Orthop 2003;123:628-32.
  9. Effect of 10% sodium ascorbate on the shear bond strength of composite resin to bleached bovine enamel. J Oral Rehabil 2004;31:1184-91.
  10. Tooth bleaching—a critical review of the biological aspects. Crit Rev Oral Biol Med 2003;14:292-304.
  11. Clinical evaluation of chemical and light-activated tooth whitening systems. Compend Contin Educ Dent 2006;27:54-62.
  12. The effect of a mild increase in temperature on tooth bleaching. Quintessence Int 2008;39:771-75.
  13. Nightguard vital bleaching. Quintessence Int 1990;20:173-76.
  14. Effect of intracoronal bleaching on external cervical root resorption. J Endod 1992;18:145-48.
  15. In vitro comparison of different types of sodium perborate used for intracoronal bleaching of discoloured teeth. Int Endod J 2002;35:433-36.
  16. pH reversal following in vitro bleaching of pulpless teeth. J Endod 1987;13:6-9.
  17. Tubular permeability to calcium hydroxide and to bleaching agents. J Endod 1989;15:362-64.
  18. Nonvital tooth bleaching: A review of the literature and clinical procedures. J Endod 2008;34:394-407.
  19. In vitro determination and quantification of 30% hydrogen peroxide penetration through dentin and cementum during bleaching. Oral Surg Oral Med Oral Pathol 1991;72:602-06.
  20. Evaluation of pH variation and cervical dentin permeability in teeth submitted to bleaching treatment. Pesqui Odontol Bras 2002;16:263-68.
  21. pH variation among materials used for intracoronal bleaching. J Endod 1991;17:376-79.
  22. Update on materials used in intracoronal bleaching. Ann R Australas Coll Dent Surg 2002;16:147-50.
  23. In vitro assessment of dentinal permeability after the use of ultrasonic-activated irrigants in the pulp chamber before internal dental bleaching. Dent Traumatol 2004;20:164-68.
  24. Effect of calcium hydroxide as a supplementary barrier in the radicular penetration of hydrogen peroxide during intracoronal bleaching in vitro. Int Endod J 2002;35:985-90.
  25. Extraradicular diffusion of hydrogen peroxide and pH changes associated with intracoronal bleaching of discoloured teeth using different bleaching agents. Int Endod J 2004;37:500-06.
  26. Effect of calcium hydroxide form and placement on root dentine pH. Int Endod J 2001;34:417-23.
  27. Nonvital tooth bleaching: Guidelines for the clinician. Quintessence Int 1995;26:597-608.
  28. Microleakage in endodontically treated teeth: Influence of calcium hydroxide dressing following bleaching. Int Endod J 2001;34:495-500.
  29. Bleaching of nonvital teeth. A clinically relevant literature review. Schweiz Monatsschr Zahnmed 2010;120:306-20.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.